The present invention relates generally to surgical devices and, more particularly, to shunts utilized in human surgical procedures for diverting normal blood flow.
The frequency of relatively complicated, traumatic vascular injuries has increased significantly in recent history, due in large part to increases in crime rates, high speed automobile accidents, and the like. Injuries to the liver, its hepatic veins, and the inferior vena cava, which leads therefrom to the right atrium of the heart, present significant technical problems to the surgeon in controlling blood loss preparatory to actual repair of the specific injuries. Indeed, major hospitals across the United States consistently report substantially high mortality rates in surgically treating traumatic vascular injuries of this type to the abdominal area. Furthermore, most deaths resulting from such injuries are caused by exsanguination, i.e. excessive blood loss.
Obviously, in emergency surgical procedures to treat hepatic and caval injuries of this type, time is of the essence to the surgeon in initially controlling blood loss. Disadvantageously, however, conventional surgical techniques for doing so are relatively time consuming and, moreover, require substantial experience and skill often possessed only by trauma surgery specialists. Basically, these techniques seek to shunt blood flow around the injured regions of the inferior vena cava and, in the case of liver, retro hepatic caval and hepatic vein injuries, around the injured hepatic caval area to isolate the liver and hepatic veins from reperfusive blood flow into the vena cava.
One conventional technique for accomplishing these purposes is to form an incision in the right atrial appendage of the heart and insert a tubular catheter downwardly through the right atrium and the inferior vena cava. The catheter is of a sufficient length that its distal end extends to approximately the location at which the renal veins from the kidneys open into the vena cava. A side opening is formed in the portion of the catheter which is disposed within the right atrium of the heart. The proximal end of the shunt extends outwardly from the right atrial appendage and is either clamped or utilized for fluid infusions. To isolate the liver and hepatic veins, tourniquets of umbilical tapes must be placed about the vena cava at locations above and below the hepatic veins. This procedure was first proposed by Drs. Schrock, Blaisdell, and Mathewson in a published article entitled, "Management of Blunt Trauma to the Liver and Hepatic Veins", Arch. Surg., Volume 96, pages 698-704 (May 1968).
An alternative procedure utilizes a tubular shunt having an inflatable balloon at one end. The balloon end of the shunt is inserted in the groin area of the patient at the saphenofemoral junction and therefrom advanced upwardly through the inferior vena cava until the balloon is located at the hepatic vein junction, whereupon the balloon is inflated to isolate the hepatic veins and liver. Side openings in the shunt permit otherwise normal blood reperfusion through the inferior vena cava to flow through the shunt. The proximal end of the shunt extends outwardly from the saphenofemoral junction and may be utilized for intravenous infusions. This procedure was suggested by Drs. Pilcher, Harman, and Moore, in The Journal of Trauma, "Retrohepatic Vena Cava Balloon Shunt Introduced Via The Sapheno-Femoral Junction", Volume 17, Number 11, pages 837-841 (November 1977).
A similar technique is discussed by Drs. Trunkey, Shires and McClelland, in "Management of Liver Trauma in 811 Consecutive Patients", Ann. Surg., Volume 179, Number 5, pages 722-728 (May 1974). A tubular catheter having an inflatable balloon at one end is also utilized in this technique. Initially, tourniquets of umbilical tape are placed around the suprarenal area of the inferior vena cava and a venotomy formed in the cava between the tourniquets. The shunt is cut to a length estimated to correspond to the caval length between the diaphragm and a point below the venotomy for the particular patient. After releasing the superior tourniquet, the balloon end of the shunt is inserted through the venotomy and advanced upwardly through the vena cava to the patient's diaphragm, whereupon the balloon is inflated to occlude the hepatic caval openings. The opposite, proximal end of the shunt is inserted through the venotomy immediately after release of the inferior tourniquet. Each tourniquet is then reapplied to control bleeding.
While these techniques have significantly advanced the practice of trauma surgery and improved the mortality experience thereof, concern still exists that these procedures require a level of experience and skill generally not possessed by non-trauma surgeons and, furthermore, may be overly time-consuming. Accordingly, a need exists for a suitable means of shunting the inferior vena cava during trauma surgery to isolate the hepatic veins and liver which may be easily and quickly employed by substantially any surgeon.